BYLINE: By Clive Cookson
Scientists yesterday heard of a new environmental hazard from genetic engineering. Experiments
at the Institute of Terrestrial Ecology's Furzebrook research station
suggest virus resistance could spread more readily from genetically modified
to weeds than researchers had realised. The research means that
regulators should approach with extreme caution any crops engineered to resist
viral diseases, the British Association conference heard.

The agricultural biotechnology industry has put considerable research into
developing such crops, though none are yet ready for commercial
approval in Europe; virus-resistant squash (marrow) has been
approved in the US. Alan Gray, head of Furzebrook, said
viruses played a bigger role in controlling weeds than
ecologists had realised. " Ecologists have neglected plant
viruses because they are hard to find, but they can act as
important biological control factors for weeds," he said.

The Furzebrook researchers studied four viruses found widely
in wild cabbages and black mustard, wild plants in the brassica
family that could exchange genes with several crops including
oilseed rape. The implication is that virus resistance could
spread from genetically engineered crops to their wild
relatives, which would then become more prolific weeds.
"More research on this question is urgently needed to improve
risk assessment for genetically modified crops," said Prof
Gray, a member of the government's advisory committee on
releases into the environment.

Prof Gray said, however, that other categories of genetic
modification, including herbicide resistance, appeared to be
ecologically acceptable.